Injection-molded air intake manifold for a v-style engine

Abstract

An improved air intake manifold for a V-style internal combustion engine comprising three individual injection molded sections joined by friction welding of flanged mating elements. Each section is formed of a high-melting temperature composite polymer. The welds are all on the exterior of the manifold. The mating surfaces are formed to be directly accessible to welding apparatus and are so oriented that friction welding may be carried out by relative motion between the components in the axial direction. When joined, the lower and middle sections form the individual air distribution runners from the plenum to the intake ports in the engine heads. The lower and middle sections are so configured that each such runner crosses the valley of the engine, providing great strength and rigidity to the module. All runners are identical, so that air flows from the plenum to the individual cylinders are substantially identical. The middle and upper sections may be rotationally symmetrical about a vertical axis, preventing mis-orientation during assembly. Modifications may be made to any one of the sections without requiring retooling of molds for the other two sections, provided the configurations of the mating surfaces are unchanged.